1. Field of the Invention
The present invention relates to a noise absorber which is to be mounted at a cable of an electronic device such as a personal computer, a video game device or the like.
2. Discussion of Background
This type of noise absorber in the known art includes, for instance, that disclosed in Japanese Examined Utility Model Publication No. 32718/1994, in which a pair of ferrites that are combined in such a manner that a cable passage is formed between them, are enclosed with a cover.
The cable may be wound around this type of noise absorber once or twice by the user in order to improve the electrical characteristics. However, when it is used in this manner, the cable is exposed at the external circumferential portion of the cover and this exposed portion of the cable is likely to become damaged. As a means for preventing the exposed portion of the cable from becoming damaged, a method in which the exposed portion of the cable is covered with heat-shrink tube, which becomes thermally contracted onto the exposed portion to enclose and protect it, is adopted in the prior art.
However, if external connectors are mounted at the two ends of the cable, it is necessary to pass the external connectors through the heat-shrink tube in order to enclose the cover and the exposed portion of the cable with the heat-shrink tube.
Thus, if the internal diameter of the heat-shrink tube is smaller than the external diameter of the external connectors, the heat-shrink tube cannot be mounted.
The problem discussed above can be avoided by setting the internal diameter of the heat-shrink tube larger than the external diameter of the external connectors. However, in that case, the internal diameter of the heat-shrink tube will become considerably larger than the external diameter of the exposed portion of the cable in the noise absorber, resulting in a gap formed between the contracted heat-shrink tube cover and the exposed portion of the cable. This presents a problem in that the heat-shrink tube will not fit the noise absorber tightly, which, in the worst case, will result in the heat-shrink tube coming off.
In addition, if the noise absorber described above is mounted at the cable of a computer used by a child, the noise absorber may be taken off the cable by the child, which will result in the noise absorption effect of the noise absorber being lost. At the same time, there are situations in which it is necessary to remove the mounted noise absorber from the cable.